AECM-83-0666, Final Deficiency Rept PRD-83/15 Re Defective Sprague Type 40D Capacitor on Brown Boveri Electric Low Voltage Circuit Breakers Equipped W/Solid State Trip Devices.Initially Reported on 831002.Also Reportable Per Part 21

Final Deficiency Rept PRD-83/15 Re Defective Sprague Type 40D Capacitor on Brown Boveri Electric Low Voltage Circuit Breakers Equipped W/Solid State Trip Devices.Initially Reported on 831002.Also Reportable Per Part 21

ML20080R191
Person / Time
Site:	Grand Gulf
Issue date:	10/10/1983
From:	Mcgaughy J MISSISSIPPI POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
REF-PT21-83-081-000 AECM-83-0666, AECM-83-666, AECM-83-6666, PT21-83-081-000, PT21-83-81, NUDOCS 8310170400
Download: ML20080R191 (5)

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MISSISSIPPI POWER & LIGHT COMPANY '

b Helping Build Mississippi '[ ,,

P. O. B O X 16 4 0. J A C K S O N , M I S S I S S I P P / l ,3 9 05 Oc tober 10, 1983 Y J AMES P. McGAUGHY. JR.

vice entsessme U. S. Nuclear Regulatory Commission Region 11 101 Marietta Street, N.W.

Suite 2900 Atlanta, Georgia 30303 Attention: Mr. J. P. O'Reilly, Regional Administrator

Dear Mr. O'ateilly:

EJBJECT: Grand Gulf Nuclear Station Unit 1 License No. NPF-13 Docket No. 50-416 File 0260/15525/15526/16694.4 PRD-83/15, Final Report, Brown Boveri Sprague Type 40D Capacitor AECM-83/0666 On October 7, 1983, Mississippi Power & Light Company notified Ms.

L. Watson, of your of fice, of a Reportable Deficiency at the Grand Gulf Nuclear Station (GGNS). The deficiency concerns possibly defective Sprague Type 40D Capacitors on Brown Boveri Electric (formerly ITE) low voltage circuit breakers equipped with solid state trip devices.

MP&L has determined that this deficiency is reportable under the provisions of 10CFR21 for Unit 1. This deficiency is not applicable to Unit 2 as evidenced in the Dece.nber 10, 1982, letter from Brown Boveri Electric, Inc.

tc Mr. Victor Stello, Jr. of the NRC. Attached is the final report.

Yours truly, ,

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B310170400 G31010

$s[.;i.gCDi'L' gDRADOCK05000 g Member Middle South Utilities System

Mr. J. P. O'Reilly AECM-83/0666 NRC Page 2 cc: Mr. J. B. Richard Mr. R. B. McGehee Mr. T. B. Conner Mr. Richard C. DeYoung Director Of fice of Inspection & Enforcement U. S. Nuclear Regulatory Coma.ission Washington, D.C. 20555 Mr. G. B. Taylor South Miss. Electric Power Association P. O. Box 1589 Hattiesburg, MS 39401 I

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I Attachment to AECM-83/0666 Paga 1 of 3 FINAL REPORT FOR PRD-83/15

1. Na me and address of the individual ... informing the commission:

J. P. McGaughy, Jr.

Vice-President, Nuclear P.O. Box 1640 Jackson, Mississippi 39205 This deficiency was also reported under 10CFR21 by Brown Boveri Electric, Inc. to the NRC in their letter dated December 10, 1982.

2. Identification of the facility ... which . . . contains a deficiency:

Grand Gulf Nuclear Station (GCNS) Unit 1 Port Gibson, Mississippi 39150

3. Identification of the fira . . . supplying the basic component which .. .

contains a deficiency:

Supplied to Grand Gulf by Brown Boveri, Inc. (Formerly ITE).

4. Nature of the deficiency .. . and the safety hazard which ... could be created by such a deficiency . . .:

A. Description of the Deficiency Failure of a capacitor in the solid state trip units of low voltage circuit breakers supplied by Brown Boveri (formerly ITE). The suspect trip units have serial numbers below 28300.

B. Analysis of Safety Implications The subject type of circuit breaker is used at GGNS for all Engineered Safety Feature (ESF) Load Control Center (LCC) breakers.

During the initial stages of degradation cf the capacitor, the trip unit may cause nuisance LCC breaker trips at lead currents below the trip settings. The ultimate failure condition' of the capacitor is an open circuit which will cause the trip unit not to respond to an overeurrent condition thus not tripping the LCC breaker. The LCC breaker not tripping on an overcurrent condition will result in severe damage, to the LCC breaker or possibly loss of the bus from the resultant overload condition of the bus supply breaker. Since the subject type of circuit breakers are used for all ESF LCC circuits, a

Eloss of any LCC breaker from nuisance trips or damage from overload condition could represent a substantial safety hazard.

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Attachment to AECM-83/0666 Paga 2 of 3

5. The date on which the information of such deficiency ... was obtained.

Mississippi Power and Light received information' cf the defect on April 19, 1983. We evaluated the deficiency and reported the deficiency to Ms.

L. Watson, of your of fice, as a Reportable Deficiency for Unit 1 on

• October 7, 1983. The MP&L " Responsible Of ficer," Mr. J. P. McGaughy, Jr. ,

has been notified.

6. In the case of the basic component . .. the number and location of all such components.

A letter dated December 10, 1982, from Brown Boveri Electric, Inc. , to the NRC indicated that low voltage circuit breakers with solid state trip devices were located at the following Nuclear Stations:

Detroit Edison Company Fermi Long Island Lighting Company Sho reham Duke Power Company McGuire Philadephia Electric Company Limerick '

Indiana & Michigan Cook Cincinnati Gas & Electric Zimme r Pennsylvania Power & Light Susquehanna Southern California Edison San Onofre Unics 2 and 3 Mississippi Power & Light Grand Gulf Unit #1 only

7. The corrective action which has been taken . . . the name of the individual

.. . responsible for the action; and .the length of time that has been . . .

taken to complete the action.

A. Corrective Actions Taken An investigation and inspection performed by Plant Staff determined that fif ty (50) of a possible sixty-one (61) trip units have

. capacitors that could potentially become prematurely defective in service. These trip units have serial numbers below 28300. All fifty of the trip units with the serial number less than 28300 will be replaced with trip units that have modified design features and capacitors which are designed to preclude premature failures.

B. Responsible Individual C. K. McCoy c Plant Manager i

Mississippi Power & Light Co.

Responsible for Unit 1

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Attachment to AECM-83/0666 Paga 3 of 3 C. h ngth of Time to Complete Actions Replacement of the affected trip units has been started by MP&L (approximately 25 trip units were replaced as of 9/27/83) and will be completed as soon as possible as new trip units are available from Brown-Boveri, without unnecessarily interfering with nuclear heatup. Because the failure condition is reported by the vendor to

- , be detectable through routine testing and by nuisance operations of the breaker during initial states of degradation, the normal.

preventative maintenance program will detect any problems while i awaiting delivery of new trip units from Brown Boveri.  ;

8. Any advice related to the deficiency ... that has been, is being, or will be given to purchasers or licensees:

As the deficiency did not originate with MP&L, we have no advice to offer.

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